If F(x) is supposed to be the CDF, you need to find the value of k that makes that true. Then you differentiate to find the PDF. If F(x) is supposed to be a PDF, you need to integrate and equate that to 1, to find k. It is not clear which is the case.

F(x) is the distribution function for a continuous random variable. Sorry, guess I forgot to mention it.

Ray Vickson is right. If F(x) is a cumulative distribution function, then you want to determine k by setting F(2)=1. Then differentiate to find the probability density function. I had thought it was the probability density function, in which case the procedure you outlined in post 5 is correct.

Ray Vickson is right. If F(x) is a cumulative distribution function, then you want to determine k by setting F(2)=1. Then differentiate to find the probability density function. I had thought it was the probability density function, in which case the procedure you outlined in post 5 is correct.

Thanks. But why 2? Why not also 1 ? And why does it have to equal one again?

Ok, so I just plug in 2 for x but I still use 1 and 2 when I take the integral, so the domain stays the same.

I don't understand why you want to integrate anything. Somebody has already done the integration [itex]\int_1^x f(t) dt [/itex] for you, and their answer is F(x). All you need to do is find the right value of k.

This is so basic, so if you don't know it there is something seriously wrong. My recommendation: quit the course now, you have no chance of passing.

RGV

You have been extremely arrogant. If you don't have anything meaningful to say, then just don't say anything. You are not helpful or contributing anything. You are the most arrogant poster I have seen on here.